Research in design and analysis problems arising from laboratory studies on: (1) dose-response relationships, (2) bioassay and potency estimation, (3) time to event, life table analyses, and (4) other investigations of the effects of external stimuli. In addition to work on a technique for estimating tolerance limits for chemical residue depletion in animals, which has been submitted for publication, a major effort in this research area has arisen in the analysis of data from the Clinical Center's Normal Range Study. This study has resulted in the collection of a large number of biochemical and clinical measurements taken serially for 2 1/2 years from "normal" volunteers. The object of the analysis is to characterize the distribution of each variable in order to determine values that can be considered normal. Some of the statistical techniques to be applied will be exploratory data analysis methods, including graphical techniques and outlier detection, transformation of variables, analysis of variance components, and serial correlation. The results of this project will appear in several published reports of quantitative characterizations with special reference to factors that may affect these distributions, such as smoking, drinking, and eating habits, and other demographic or socio-economic factors.